The prior art of removing Mura defect of the OLED (Organic Light-Emitting Diode) panel is similar to the LCD (Liquid Crystal Display), which getting the brightness of the each pixel on the panel first, then measuring the Mura (Japanese, the term of the display technology field means uneven brightness) and setting the ideal brightness of the Mura area, finally calculating the gray scale value or the voltage value of compensating the Mura area needed based on the Gamma curve or the gray—brightness table.
But the OLED is different from the LCD, the each pixel of the LCD Gamma curve is relatively consistent, the each pixel of the OLED Gamma curve is large-difference so that the OLED cannot in accordance with the unified compensation to the Mura.
In the prior art, estimated the corrected gray value based on the Gamma value and the ideal brightness, e.g. “Method and device for removing liquid crystal displayer Mura (CN201310695713.X)”: the corrected gray scale value of the each pixel corresponding to the input image is calculated by the corrected brightness value of the each pixel corresponding to the input image and the gamma index. The disadvantage of this method is, the deviation of the Gamma curve of the each pixel of the OLED panel, especially the Mura area is larger. Cannot achieve the desired compensation effect based on estimating the gray scale value by the uniform Gamma value or the uniform Gamma curve.
Therefore, in practice, in order to obtain an ideal correction value of the gray scale, the steps of shooting→trimming the gray scale→shooting→trimming the gray scale is repeatedly needed. Because the time is limited, the above-described method only can obtain a plurality of the correction values of the gray scale, and then obtain the remaining correction value of the gray scale by interpolating.
Assuming in 48 gray scale, the brightness of the normal area (uniform brightness area) is 48 nit, and the brightness of the Mura area is 44 nit. According to the traditional scheme, first, shooting a few specific gray scales, such as 32 gray scale, 64 gray scale, 224 gray scale, etc., and getting the correction value of the Mura area corresponding to these gray scale values. Because the Gamma characteristic of the Mura area is unknown, a single adjustment is often less than the desired effect, and is generally requires repeated shooting and trimming the gray scale to achieve the uniform brightness. Then, establishing the original gray—correction gray scale look-up table, and finally, interpolating the other correction value of the gray scale. Assuming the interpolated correction value corresponding to the gray scale 48 is gray scale 51, adjusting the gray scale in the Mura area to 51 to achieve a uniform effect of full-screen 48 nit. This method is extremely inefficient, the repeated testing is required to reach the uniform brightness.
Therefore, providing a method for calibrating brightness unevenness of the OLED display panel is needed to solve the above technical problems.